Preheat the oven to 200°C. Line a baking tray with baking paper. In a small bowl, combine the soy sauce, vinegar, sugar, lemon juice, ginger, garlic, and chilli. Stir well to dissolve the sugar.
Place the Sadia Chicken Thighs and Drumsticks in a large dish, and pour over the marinade, making sure you push some under the skin. Leave to marinate at room temperature for 15 minutes, stirring occasionally.
Add the egg and flour to the chicken and marinade. Stir to combine and coat. Crush the cornflakes; combine with the sesame seeds in a shallow plate. Dredge each piece of chicken in the cornflake mixture to coat well then place on the prepared baking tray.
Spray with oil and bake for 30 minutes, or until cooked through. Cover with foil if the cornflake coating is browning too much.
To make the spiced vinegar, combine all the ingredients in a small saucepan and heat until the sugar has dissolved. Cool.